================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: null-ptr-deref in smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:135 Read of size 4 at addr 0000000000000abc by task syz.8.1128/11518 CPU: 1 UID: 0 PID: 11518 Comm: syz.8.1128 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:135 tcp_check_req+0x69d/0x1f80 net/ipv4/tcp_minisocks.c:874 tcp_v4_rcv+0x19ab/0x4640 net/ipv4/tcp_ipv4.c:2291 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:260 dst_input include/net/dst.h:471 [inline] ip_rcv_finish net/ipv4/ip_input.c:454 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5991 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6104 process_backlog+0x442/0x15e0 net/core/dev.c:6456 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7506 napi_poll net/core/dev.c:7569 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5225 Code: fb 09 00 00 44 8b 05 59 c4 22 0f 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 9f 64 3a 00 fb 65 48 8b 1d 1e b4 4d 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc9000454f4b8 EFLAGS: 00000206 RAX: 00000000000153db RBX: ffff888026a0bc00 RCX: ffffffff81c37f8f RDX: 0000000000000000 RSI: ffffffff8de5176d RDI: ffffffff8c163a00 RBP: ffffc9000454f500 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90abae97 R11: 0000000000000000 R12: ffff8880b853a440 R13: ffff88801e685a00 R14: ffff8880b843a440 R15: ffff8880b853b270 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 unix_wait_for_peer+0x245/0x280 net/unix/af_unix.c:1639 unix_dgram_sendmsg+0x1410/0x17f0 net/unix/af_unix.c:2273 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmmsg+0x200/0x420 net/socket.c:2757 __do_sys_sendmmsg net/socket.c:2784 [inline] __se_sys_sendmmsg net/socket.c:2781 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2781 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9aa1b8eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9aa2b10038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f9aa1de5fa0 RCX: 00007f9aa1b8eec9 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f9aa1c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9aa1de6038 R14: 00007f9aa1de5fa0 R15: 00007ffcf3ed8438 ================================================================== Oops: general protection fault, probably for non-canonical address 0xdffffc0000000157: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000ab8-0x0000000000000abf] CPU: 1 UID: 0 PID: 11518 Comm: syz.8.1128 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:smc_tcp_syn_recv_sock+0xb8/0x4b0 net/smc/af_smc.c:135 Code: ad bc 0a 00 00 be 04 00 00 00 44 8b bb 1c 04 00 00 4c 89 ef e8 59 5f e7 f6 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 34 RSP: 0018:ffffc90000a08768 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff888078635e80 RCX: ffffffff817a563f RDX: 0000000000000157 RSI: ffffffff8220e447 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 6e696c6261736944 R12: 0000000000000000 R13: 0000000000000abc R14: ffffc90000a08838 R15: 0000000000000000 FS: 00007f9aa2b106c0(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005651d9b565b8 CR3: 00000000564f8000 CR4: 0000000000350ef0 Call Trace: tcp_check_req+0x69d/0x1f80 net/ipv4/tcp_minisocks.c:874 tcp_v4_rcv+0x19ab/0x4640 net/ipv4/tcp_ipv4.c:2291 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:260 dst_input include/net/dst.h:471 [inline] ip_rcv_finish net/ipv4/ip_input.c:454 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5991 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6104 process_backlog+0x442/0x15e0 net/core/dev.c:6456 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7506 napi_poll net/core/dev.c:7569 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5225 Code: fb 09 00 00 44 8b 05 59 c4 22 0f 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 9f 64 3a 00 fb 65 48 8b 1d 1e b4 4d 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc9000454f4b8 EFLAGS: 00000206 RAX: 00000000000153db RBX: ffff888026a0bc00 RCX: ffffffff81c37f8f RDX: 0000000000000000 RSI: ffffffff8de5176d RDI: ffffffff8c163a00 RBP: ffffc9000454f500 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90abae97 R11: 0000000000000000 R12: ffff8880b853a440 R13: ffff88801e685a00 R14: ffff8880b843a440 R15: ffff8880b853b270 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 unix_wait_for_peer+0x245/0x280 net/unix/af_unix.c:1639 unix_dgram_sendmsg+0x1410/0x17f0 net/unix/af_unix.c:2273 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmmsg+0x200/0x420 net/socket.c:2757 __do_sys_sendmmsg net/socket.c:2784 [inline] __se_sys_sendmmsg net/socket.c:2781 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2781 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9aa1b8eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9aa2b10038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f9aa1de5fa0 RCX: 00007f9aa1b8eec9 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f9aa1c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9aa1de6038 R14: 00007f9aa1de5fa0 R15: 00007ffcf3ed8438 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:smc_tcp_syn_recv_sock+0xb8/0x4b0 net/smc/af_smc.c:135 Code: ad bc 0a 00 00 be 04 00 00 00 44 8b bb 1c 04 00 00 4c 89 ef e8 59 5f e7 f6 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 34 RSP: 0018:ffffc90000a08768 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff888078635e80 RCX: ffffffff817a563f RDX: 0000000000000157 RSI: ffffffff8220e447 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 6e696c6261736944 R12: 0000000000000000 R13: 0000000000000abc R14: ffffc90000a08838 R15: 0000000000000000 FS: 00007f9aa2b106c0(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005651d9b565b8 CR3: 00000000564f8000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 00 00 add %al,(%rax) 2: 44 8b 05 59 c4 22 0f mov 0xf22c459(%rip),%r8d # 0xf22c462 9: 45 85 c0 test %r8d,%r8d c: 0f 85 be 01 00 00 jne 0x1d0 12: 4c 89 e7 mov %r12,%rdi 15: e8 a4 f6 ff ff call 0xfffff6be 1a: e8 9f 64 3a 00 call 0x3a64be 1f: fb sti 20: 65 48 8b 1d 1e b4 4d mov %gs:0x124db41e(%rip),%rbx # 0x124db446 27: 12 * 28: 48 8d bb 18 16 00 00 lea 0x1618(%rbx),%rdi <-- trapping instruction 2f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 36: fc ff df 39: 48 89 fa mov %rdi,%rdx 3c: 48 rex.W 3d: c1 .byte 0xc1